Hard to say. Where are you from? Sony ANZ is Sony Australia and New Zealand. Do you have any reason to believe that Sony Australia would know about you? (like you live there?) Unless you care about joining a Sony portal, just delete the email and move on.

I am based in Australia, Brisbane to be more precise. Sony may possibly know about me (i think), but all my Vegas purchases were made in the US portal going back to 2008. The timing of the email coincides with the Magix acquisition of Vegas, but phishers also use such opportunities to steal identities. I might sit on this email for a while.

Sounds like it could feasibly be legitimate. I went to the web site and it looks like a Sony site. They even have a downloadable app on Google Play and the iTunes App Store. It might be real but it's up to you to determine if you want to sign up. I would just ignore it.